Android的SurfaceView：图像显示后视频 [英] Android SurfaceView: Show Video after Images
本文介绍了Android的SurfaceView：图像显示后视频的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想在同一个SurfaceView一对夫妇的图像后播放视频。如果我显示图片视频之后，一切工作正常。但是如果我想的影像后播放视频时，SurfaceView保持空白（黑色）。任何人都可以帮忙吗？这似乎是清除或重置SurfaceView的问题！
在SurfaceView的code（自定义SurfaceView !!!）：
公共类MySurfaceView扩展SurfaceView实现SurfaceHolder.Callback，MediaPlayer.OnCompletionListener { 私人位图图像;
私人的MediaPlayer媒体播放器;
私人列表＆LT; MySurfaceListener＆GT; objectsToCall =新的ArrayList＆LT;＆GT;（）; 公共MySurfaceView（上下文的背景下）{
超级（上下文）;
。getHolder（）的addCallback（本）;
} 公共无效addOnPlayingFinishedListener（MySurfaceListener监听）{
objectsToCall.add（监听）;
} 公共无效notifyAllOnPlayingFinishedListener（）{
对于（MySurfaceListener L：objectsToCall）{
l.onMediaPlayFinished（）;
}
} 公共静态INT calculateInSampleSize（BitmapFactory.Options选项，诠释reqWidth，诠释reqHeight）{
// Helper方法来缩小图像文件
} 公共静态位图德codeSampledBitmapFromFile（字符串路径，INT reqWidth，诠释reqHeight）{ //为图像文件的另一种辅助方法，
} 公共无效的drawImage（字符串路径，最终诠释DURATION毫秒）{
this.image =去codeSampledBitmapFromFile（路径，1920，1080）;
帆布帆布= NULL;
尝试{
帆布= getHolder（）lockCanvas（空）。
同步（getHolder（））{
的onDraw（帆布）;
}
}赶上（例外五）{
e.printStackTrace（）;
} {最后
如果（帆布！= NULL）{
。getHolder（）unlockCanvasAndPost（画布）;
}
image.recycle（）;
图像= NULL;
} 螺纹showPictureTimer =新主题（新的Runnable（）{
@覆盖
公共无效的run（）{
尝试{
视频下载（DURATION毫秒）;
}赶上（InterruptedException的E）{
e.printStackTrace（）;
}
}
}）;
showPictureTimer.start（）;
尝试{
showPictureTimer.join（）;
}赶上（InterruptedException的E）{
e.printStackTrace（）;
}
notifyAllOnPlayingFinishedListener（）;
} 公共无效的playVideo（字符串路径）{
尝试{
媒体播放器=新的MediaPlayer（）;
mediaPlayer.setOnCompletionListener（本）;
mediaPlayer.setDisplay（getHolder（））;
mediaPlayer.setDataSource（路径）;
媒体播放器prepare（）。
mediaPlayer.start（）;
}赶上（抛出：IllegalArgumentException五）{
Log.d（MyMediaPlayerControl，e.getMessage（））;
}赶上（IllegalStateException异常五）{
Log.d（MyMediaPlayerControl，e.getMessage（））;
}赶上（IOException异常五）{
Log.d（MyMediaPlayerControl，e.getMessage（））;
}
} @覆盖
保护无效的onDraw（帆布油画）{
super.onDraw（画布）;
canvas.drawColor（Color.BLACK）;
canvas.drawBitmap（this.image，0，0，新的油漆（））;
} 公共无效surfaceChanged（SurfaceHolder为arg0，ARG1 INT，INT ARG2，诠释ARG3）{
Log.e（对myApp，surfaceChanged）;
} 公共无效surfaceCreated（SurfaceHolder为arg0）{
Log.e（对myApp，surfaceCreated）;
} 公共无效surfaceDestroyed（SurfaceHolder为arg0）{
Log.e（对myApp，surfaceDestroyed）;
} @覆盖
公共无效onCompletion（MediaPlayer的MP）{
如果（媒体播放器！= NULL）{
mediaPlayer.stop（）;
mediaPlayer.release（）;
媒体播放器= NULL;
}
notifyAllOnPlayingFinishedListener（）;
}
}
和其中给出了文件路径的表面视图，用于播放（不应是问题）的螺纹
公共类MediaControlThread继承Thread实现MySurfaceListener {
公共静态列表＆LT;串GT; medialist中=新的ArrayList＆LT;串GT;（）;
MyMediaActivity活动;
私人MySurfaceView surfaceView;
私人INT currentVideo = 0; 公共MediaControlThread（MyMediaActivity活动）{
this.activity =活动;
this.surfaceView = activity.getSurfaceView（）;
this.surfaceView.addOnPlayingFinishedListener（本）;
} @覆盖
公共无效的run（）{
尝试{
而（mediaList.size（）== 0）{
视频下载（1000）;
}
视频下载（3000）;
}赶上（InterruptedException的E）{
e.printStackTrace（）;
}
playMedia（mediaList.get（currentVideo））;
} 私人无效playMedia（字符串mediaPath）{
如果（checkFileForImage（mediaPath））{
surfaceView.drawImage（mediaPath，2000年）;
}其他{
surfaceView.playVideo（mediaPath）;
}
} 私人布尔checkFileForImage（字符串文件名）{
字符串文件= fileName.toLowerCase（）;
返回file.endsWith（JPG）||
file.endsWith（IMG）||
file.endsWith（BMP）||
file.endsWith（JPEG）||
file.endsWith（。ICO）||
file.endsWith（TIF。）;
} @覆盖
公共无效onMediaPlayFinished（）{
surfaceView.invalidate（）;
surfaceView.destroyDrawingCache（）;
currentVideo ++;
如果（currentVideo＆GT; mediaList.size（） - 1）{
currentVideo = 0;
}
playMedia（mediaList.get（currentVideo））;
}
}
解决方案
这是不幸的是，预期的行为。由于Android的一个怪癖，一旦你画在地面与帆布你不能做任何事情。
您有三种选择：
- 与OpenGL ES的，而不是画布绘制图像。一旦分离GLES你可以回去显示视频。
- present图像作为单帧视频。这工作得很好像清屏琐碎的事情，但对于动态内容的糟糕的选择。
- 使用一个的FrameLayout叠加一个ImageView的或自定义视图。显示视图时要显示的图像，将其隐藏，否则。只要表面上是在默认Z-深度，ImageView的会出现在它的面前，并掩盖它。
I want to play a video after a couple of images in the same SurfaceView. If I show images AFTER videos, everything works fine. But if I want to play a video after the images, the SurfaceView stays blank (black). Can anyone help? It seems to be a problem of clearing or resetting the SurfaceView!
The code of the SurfaceView (custom SurfaceView!!!):
public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback, MediaPlayer.OnCompletionListener {
private Bitmap image;
private MediaPlayer mediaPlayer;
private List<MySurfaceListener> objectsToCall = new ArrayList<>();
public MySurfaceView(Context context) {
super(context);
getHolder().addCallback(this);
}
public void addOnPlayingFinishedListener(MySurfaceListener listener) {
objectsToCall.add(listener);
}
public void notifyAllOnPlayingFinishedListener() {
for(MySurfaceListener l : objectsToCall) {
l.onMediaPlayFinished();
}
}
public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Helper method to scale down the image files
}
public static Bitmap decodeSampledBitmapFromFile(String path, int reqWidth, int reqHeight) {
// Another helper method for the image files
}
public void drawImage(String path, final int durationMs) {
this.image = decodeSampledBitmapFromFile(path, 1920, 1080);
Canvas canvas = null;
try {
canvas = getHolder().lockCanvas(null);
synchronized (getHolder()) {
onDraw(canvas);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (canvas != null) {
getHolder().unlockCanvasAndPost(canvas);
}
image.recycle();
image = null;
}
Thread showPictureTimer = new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(durationMs);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
showPictureTimer.start();
try {
showPictureTimer.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
notifyAllOnPlayingFinishedListener();
}
public void playVideo(String path) {
try {
mediaPlayer = new MediaPlayer();
mediaPlayer.setOnCompletionListener(this);
mediaPlayer.setDisplay(getHolder());
mediaPlayer.setDataSource(path);
mediaPlayer.prepare();
mediaPlayer.start();
} catch (IllegalArgumentException e) {
Log.d("MyMediaPlayerControl", e.getMessage());
} catch (IllegalStateException e) {
Log.d("MyMediaPlayerControl", e.getMessage());
} catch (IOException e) {
Log.d("MyMediaPlayerControl", e.getMessage());
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.BLACK);
canvas.drawBitmap(this.image, 0, 0, new Paint());
}
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
Log.e("myApp", "surfaceChanged");
}
public void surfaceCreated(SurfaceHolder arg0) {
Log.e("myApp", "surfaceCreated");
}
public void surfaceDestroyed(SurfaceHolder arg0) {
Log.e("myApp", "surfaceDestroyed");
}
@Override
public void onCompletion(MediaPlayer mp) {
if (mediaPlayer != null) {
mediaPlayer.stop();
mediaPlayer.release();
mediaPlayer = null;
}
notifyAllOnPlayingFinishedListener();
}
}
And the thread which gives the file paths to the surface view for playing (should not be the problem):
public class MediaControlThread extends Thread implements MySurfaceListener {
public static List<String> mediaList = new ArrayList<String>();
MyMediaActivity activity;
private MySurfaceView surfaceView;
private int currentVideo = 0;
public MediaControlThread(MyMediaActivity activity) {
this.activity = activity;
this.surfaceView = activity.getSurfaceView();
this.surfaceView.addOnPlayingFinishedListener(this);
}
@Override
public void run() {
try {
while(mediaList.size() == 0) {
Thread.sleep(1000);
}
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
playMedia(mediaList.get(currentVideo));
}
private void playMedia(String mediaPath) {
if(checkFileForImage(mediaPath)) {
surfaceView.drawImage(mediaPath, 2000);
} else {
surfaceView.playVideo(mediaPath);
}
}
private boolean checkFileForImage(String fileName) {
String file = fileName.toLowerCase();
return file.endsWith(".jpg") ||
file.endsWith(".img") ||
file.endsWith(".bmp") ||
file.endsWith(".jpeg") ||
file.endsWith(".ico") ||
file.endsWith(".tif");
}
@Override
public void onMediaPlayFinished() {
surfaceView.invalidate();
surfaceView.destroyDrawingCache();
currentVideo++;
if (currentVideo > mediaList.size() - 1) {
currentVideo = 0;
}
playMedia(mediaList.get(currentVideo));
}
}
解决方案
That is, unfortunately, the expected behavior. Due to a quirk in Android, once you've drawn on a Surface with Canvas you can't do anything else.
You have three choices:
- Draw the image with OpenGL ES rather than Canvas. Once you detach GLES you can go back to showing videos.
- Present the image as a single-frame video. This works nicely for trivial things like blanking the screen, but is a poor choice for dynamic content.
- Use a FrameLayout to overlay an ImageView or custom View. Show the View when you want to show an image, hide it otherwise. So long as the Surface is at the default Z-depth, the ImageView will appear in front of it and obscure it.
这篇关于Android的SurfaceView：图像显示后视频的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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